The prevalence of adverse reactions to foods is higher in children with atopic disease, specifically asthma and atopic dermatitis. It has been demonstrated that ingestion of food allergens in susceptible individuals causes an increase in bronchial hyperresponsiveness, manifested by an increased sensitivity to methacholine. The hypothesis of this study is that, in patients with asthma in whom a food is shown to produce adverse reactions, the chronic ingestion of the food may contribute to the chronic inflammation in the airways and to the increase in bronchial hyperresponsiveness. The elimination of the food from the diet will result in amelioration of the asthma severity and in a decrease in bronchial hyperresponsiveness.